Be nice. Privilege is not nice.
In today's near vehemently anti-smoker world, it is best to give no one the opportunity to look even further down their snooty snouts at we, Brothers and Sisters of the Leaf. True, there is much to be said for a "screw you, I'll do what I want," mentality -- at the end of the day, we are social animals and must learn to live in accordance with that truth. Also, no one is asking you to bow before a queen.
An important thing to bear in mind is that you are straddling the fine line between asking and notifying. Before that, however, you are in no way expected to listen to some layman (or even professional) schpiel regarding the medical hazards of tobacco use.
Allow me now to digress. Here, take a fleuron --
Asking versus Alerting:
We are being nice. We are saying, "Mind if I smoke?" They very well might mind. Perhaps, they might even be made aware of the possibility of minding elsewhere -- dependant upon the scenario and who of the lot of you arrived first to said scenario. If they do mind, then you two have a thing to work out. Let's enter negotiations as adults. Or, retreat out of their airspace. Whichever --
If you wish to look at it in hawk or in dove terms, is up to you. I beseech you, however, to give no one usable fodder to aid them in inciting further anti-smoking/er sentiment.
We have seen the variances that occur from asking and telling, and can furthermore imagine any infinite numbers of in-betweens. What of this one, however:
Asking Permission When Alone
Smoking is no small part ritual and perhaps more so, meditation. This would be the metaphysical ritual. This would be, too, metaphysical meditation. This would be an announcement of intent.
You are asking everyone and no one.
We are asking the universe. We are too ignoring the universe. The deep ritual which leads to deeper meditation has the end game of both saluting and turning our backs to, the universe. You are simply, again, announcing intent. Many rituals, many more meditations, begin in this way. I ask that you try this tact.
I also ask that you don't bother me with the results. I'm not result oriented -- I'm more an "idea guy."
[Bear in mind that this commandment is the one which supplies you the most rope with which to hang yourself -- and too to bring smokers, as a whole, with you to the gallows.]
Gentlepersons, as always, thank you ever so kindly and respectfully for reading.
You can, and furthermore should, read The Eleven (11) Commandments of Cigar Etiquette
in their gloriously sage entirety HERE.